I would use syfe's 0.4% as S$100k is not too high to hit
Those etfs' ter are 0.6% and 0.58% btw.
So syfe is actually the lowest now based on 0.4%, about 0.1% more than sti etf
In terms of benchmark, I wouldn't compare against STI ETF.
First, Singapore is a very inefficient market with high fees. Secondly, anybody with a reasonable sum of money should be diversifying geographically and as such, investing outside of SGX. All of a sudden, the benchmark becomes global ETFs that charge 0.1-0.5% and not the STI ETF.
I don't see the value-add that Syfe is providing. In fact, given how correlated REITs are with bonds, I would be annoyed any time they shift towards bonds. The risk profile stays similar while the returns drop. I hope they publish some backtesting results with and without "ARI" (that go further back than 2017...).
The value in this is perhaps the re-balancing and the reduction in transaction costs which is worth maybe 0.2% annually - not 0.4-0.6%.
-- If you want a really hands-off approach, 0.4% is ok, but I would really want proof that this ARI thing is going to help rather than hurt.